document.write( "Question 974628: A parts manufacturer has 40 kg of a copper and zinc alloy which contains 8 kg of zinc. Find the amount of copper which must be added if the manufacturer requires a new alloy containing 10% zinc. \n" ); document.write( "
Algebra.Com's Answer #596527 by josgarithmetic(39618)\"\" \"About 
You can put this solution on YOUR website!
Copper will dilute the Zinc.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%2840%288%2F40%29%29%2F%2840%2Bz%29=0.10\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"%2840%281%2F5%29%29%2F%28z%2B40%29=1%2F10\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"8%2F%28z%2B40%29=1%2F10\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"z%2B40=80\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"z=40\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "NOTE: This seemed a little easier converting fully into regular fractions than percents or mixing percents with regular fractions. Usually the choice is yours when you solve, depending on instructions.
\n" ); document.write( "
\n" );